Since 1990, the standard deviation of daily price changes in front-month Brent crude (LCOc1) has been 1.64% (ignoring signs). Today’s current change is 6.1% (at time of writing) That is approximately 3.72 standard deviations IF price movements were normally distributed (which we know they are not), price movements should be within 1 standard deviation about 66% of the time, 2 standard deviations 95% of the time, 3 standard deviations about 99.7% of the time, and 4 standard deviations 99.99% of the time